On Fri, Mar 22, 2024 at 01:32:30PM +0100, Mikulas Patocka wrote: > > > On Fri, 22 Mar 2024, Ming Lei wrote: > > > If logical block becomes mismatched by reconfiguration, the whole DM stack can't work: > > > > - at the beginning, DM is over NVMe(512 bs), DM & NVMe lbs is 512 > > - later, nvme is reconfigured and its lbs becomes 4k, but DM's lbs can't > > be updated > > - then unaligned IO is submitted to NVMe > > > > So DM _never_ works with mis-matched logical block size because of > > reconfigure, and same with MD. > > It can work. If a filesystem has 4k block size and it is used on a block Here 'work' means it supports any allowed block size, instead of 4KB only or if balabala... The DM device advertises its lbs as 512, application & FS should be free to read/write 512 aligned data, right? Thanks, Ming
